Develop custom campaign element

Hi creatio community,

I am developing a custom campaign element (sms element) as described in this link: https://academy.creatio.com/docs/8.x/dev/development-on-creatio-platform/platform-customization/classic-ui/marketing-campaigns-basics/examples/implement-a-campaign-element  

I have implemented it and it works fine. The thing that I'm missing here which is very important in my case, is that I want the "SmsText" parameter to have dynamic values inside it. For example in the "SmsText" message value i want to have "Hi " + Contact.Name. This solution provides only static text which in most scenarios the sms message text should be dynamic. 

Could you give any idea/solution on how i can implement in my case?

Thanks